This is an old children's game, anyone who trod on the cracks between the paving stones was out, until only oneplayer was left, he or she was then declared the winner.
Step on a crack, break your mother's back– Most of us know the old rhyme “Step on a crack, break your mother’s back.” Whether the rhyme is the cause of, or a result of, this superstition is uncertain, though belief in it persists in many people today, even if subconsciously. Come to think of it, avoiding sidewalk cracks is probably a good policy for anyone who wants to avoid tripping.
This is going from top to bottom, right to left on your keyboard with spaces in between all the letter. You do this when your so board that you refuse to do something productive and start searching random things.
James was so board that he started typing m n b v c x z l k j h g f d s a p o i u y t r e w q instead of reading his book.